The 20-year-old confessed Thursday to his involvement in the slayings of 4 men who'd been reported missing

NBC10's Erin Coleman has the latest on the Cosmo DiNardo case. Coleman speaks to NBC10's Deanna Durante who has details from Arcadia University that banned DiNardo from campus last fall due to verbal incidents.

Their 68-acre farm about four miles outside New Hope in Bucks County, Pennsylvania, cost a cool $5.4 million in September 2005. But Antonio and Sandra DiNardo, whose fortune stems from trucking and concrete, weren’t done adding to their estate.

Less than a year later, the couple bought an adjacent property with a farmhouse built in 1821 for $450,000, according to county property records.

In December 2008, they bought another couple of adjacent acres for $500,000 to complete a massive property along Lower York Road, which has become the center of a search for four missing young men and garnered national attention with the DiNardos' son named a person of interest in the case.

Dozens of local police and FBI agents scoured the family's farm for two days, using backhoes and other earth-moving equipment in what the county district attorney on Wednesday called the county's biggest search in recent history.

Cosmo DiNardo
Photo credit: Bucks County District Attorney's Office

Cosmo DiNardo, 20, the son of Antonio and Sandra, was ordered held on $5 million cash bail for allegedly being in possession of a car belonging to one of the missing men. The new arrest on Wednesday came a day after his family posted $100,000 bond to free the young man after he was initially held on gun charges while District Attorney Matt Weintraub described him as a person of interest in the confounding case.

According to an affidavit obtained by NBC10, DiNardo was accused of possessing a 20-gauge shotgun and ammunition in February despite being barred from owning a firearm due to a history of mental illness that included an involuntary commitment. A district judge dismissed the charge in May, but the district attorney had authorized for it to be refiled on Monday.

DiNardo's attorney, Fortunato Perri Jr., had no comment to reporters as he arrived to a court appearance with the DiNardo parents on Thursday morning.

Mark Sturgis, 22, of Pennsburg, Montgomery County, 21-year-old Thomas Meo, of Plumstead Township; Dean Finocchiaro, 19, of Middletown Township and Jimi Tar Patrick, 21, of Newtown Township all vanished last week. Weintraub said the four and DiNardo all apparently knew each other.

How exactly Cosmo DiNardo came to be the focus of the investigation and why his parents’ farm was in law enforcement’s cross hairs remained shrouded in mystery.

What is known is that the young man comes from a family that has built a fortune on real estate in Philadelphia, Montgomery and Bucks counties. His grandfather, also named Cosmo DiNardo, owned several properties, with property records dating back to the 1970s showing a mix of residential and commercial rental properties.

The diverse holdings include a property leased to a behavioral health non-profit on Adams Avenue in Northeast Philadelphia that brings in as much as $32,000 a month, and a multi-unit apartment house on West Avenue in Jenkintown.

The elder Cosmo DiNardo died in 1997 at the age of 55. He had lived with his wife on Mayfield Avenue in Elkins Park since 1974. It’s not clear how he got his start — or the initial capital required — to begin buying real estate.

But his next purchase was the house on Wayland Circle in Bensalem where his grandson was twice arrested this week. Antonio and Sandra DiNardo continue to use that suburban home as the base for their real estate and business holdings.

Between 1979 and 1989, Cosmo DiNardo bought three commercial properties and the Jenkintown apartment house.

The first purchase was a strip of storefronts at 1016 Cottman Avenue for $67,500 in 1979, which was sold in 2004 by his son Antonio for $425,000.

The next was 3159 Summerdale Avenue, bought for an unknown amount in 1981.

A third commercial property, bought in 1986 for $95,000, is 10 Shady Lane in Rockledge, Montgomery County. It’s currently rented to a dentist.

As his son came of age, Cosmo and Antonio DiNardo shared one real estate deal before Antonio eventually took over. The elder Cosmo and Antonio DiNardo purchased a Philadelphia house on Longmead Lane for $50,000 in early 1989 and flipped it two years later for $210,000.

In the late 1990s and 2000s, Antonio DiNardo purchased four more properties, two in Philadelphia and two in Bensalem. In 1998, DiNardo bought 4455-65 Castor Avenue for $94,000. It is home to the family concrete business called Metro Ready Mix and Supply.

The other property on Adams Avenue, purchased for $140,000 in 2001, is leased through 2032, according to property records, to a health care non-profit called The Bridge.

One of the Bensalem properties, 3636-3649 Hulmeville Road, which was bought in 2004 for $450,000, is home to the family’s other business, Bella Trucking.

The following year, the DiNardos began collecting the farmland outside New Hope that would become the scene for the evolving mystery surrounding four missing men and a son who now sits inside Bucks County Jail.

As investigators converged on the family's estate, the DiNardos have remained tight-lipped.

But the family's attorney, Perri Jr., released a statement Wednesday on behalf of Antonio and Sandra DiNardo expressing sympathy for the families of the missing and asserting their cooperation in the investigation.

"As parents, Mr. and Mrs. DiNardo sympathize with the parents and families of the missing young men and they are cooperating in every way possible with the investigation being conducted by law enforcement," the lawyer wrote hours before the discovery of human remains on their property.